System.Data.Tests.DataColumnCollectionTest.Add C# (CSharp) Method

        public void Add()
        {
            var Table = new DataTable("test_table");
            DataColumnCollection cols = Table.Columns;
            DataColumn c = null;
            cols.Add();
            cols.Add();

            for (int i = 0; i < 2; i++)
            {
                c = cols[i];
                Assert.True(c.AllowDBNull);
                Assert.False(c.AutoIncrement);
                Assert.Equal(0L, c.AutoIncrementSeed);
                Assert.Equal(1L, c.AutoIncrementStep);
                Assert.Equal($"Column{i + 1}", c.Caption);
                Assert.Equal("Element", c.ColumnMapping.ToString());
                Assert.Equal($"Column{i + 1}", c.ColumnName);
                Assert.Null(c.Container);
                Assert.Equal(typeof(string), c.DataType);
                Assert.Equal(DBNull.Value, c.DefaultValue);
                Assert.False(c.DesignMode);
                Assert.Equal("", c.Expression);
                Assert.Equal(0, c.ExtendedProperties.Count);
                Assert.Equal(-1, c.MaxLength);
                Assert.Equal("", c.Namespace);
                Assert.Equal(i, c.Ordinal);
                Assert.Equal("", c.Prefix);
                Assert.False(c.ReadOnly);
                Assert.Null(c.Site);
                Assert.Equal("test_table", c.Table.TableName);
                Assert.Equal($"Column{i + 1}", c.ToString());
                Assert.False(c.Unique);
            }

            cols.Add("test1", typeof(int), "");
            cols.Add("test2", typeof(string), "Column1 + Column2");

            c = cols[2];
            Assert.True(c.AllowDBNull);
            Assert.False(c.AutoIncrement);
            Assert.Equal(0L, c.AutoIncrementSeed);
            Assert.Equal(1L, c.AutoIncrementStep);
            Assert.Equal("test1", c.Caption);
            Assert.Equal("Element", c.ColumnMapping.ToString());
            Assert.Equal("test1", c.ColumnName);
            Assert.Null(c.Container);
            Assert.Equal(typeof(int), c.DataType);
            Assert.Equal(DBNull.Value, c.DefaultValue);
            Assert.False(c.DesignMode);
            Assert.Equal("", c.Expression);
            Assert.Equal(0, c.ExtendedProperties.Count);
            Assert.Equal(-1, c.MaxLength);
            Assert.Equal("", c.Namespace);
            Assert.Equal(2, c.Ordinal);
            Assert.Equal("", c.Prefix);
            Assert.False(c.ReadOnly);
            Assert.Null(c.Site);
            Assert.Equal("test_table", c.Table.TableName);
            Assert.Equal("test1", c.ToString());
            Assert.False(c.Unique);

            c = cols[3];
            Assert.True(c.AllowDBNull);
            Assert.False(c.AutoIncrement);
            Assert.Equal(0L, c.AutoIncrementSeed);
            Assert.Equal(1L, c.AutoIncrementStep);
            Assert.Equal("test2", c.Caption);
            Assert.Equal("Element", c.ColumnMapping.ToString());
            Assert.Equal("test2", c.ColumnName);
            Assert.Null(c.Container);
            Assert.Equal(typeof(string), c.DataType);
            Assert.Equal(DBNull.Value, c.DefaultValue);
            Assert.False(c.DesignMode);
            Assert.Equal("Column1 + Column2", c.Expression);
            Assert.Equal(0, c.ExtendedProperties.Count);
            Assert.Equal(-1, c.MaxLength);
            Assert.Equal("", c.Namespace);
            Assert.Equal(3, c.Ordinal);
            Assert.Equal("", c.Prefix);
            Assert.True(c.ReadOnly);
            Assert.Null(c.Site);
            Assert.Equal("test_table", c.Table.TableName);
            Assert.Equal("test2 + Column1 + Column2", c.ToString());
            Assert.False(c.Unique);

            c = new DataColumn("test3", typeof(int));
            cols.Add(c);

            c = cols[4];
            Assert.True(c.AllowDBNull);
            Assert.False(c.AutoIncrement);
            Assert.Equal(0L, c.AutoIncrementSeed);
            Assert.Equal(1L, c.AutoIncrementStep);
            Assert.Equal("test3", c.Caption);
            Assert.Equal("Element", c.ColumnMapping.ToString());
            Assert.Equal("test3", c.ColumnName);
            Assert.Null(c.Container);
            Assert.Equal(typeof(int), c.DataType);
            Assert.Equal(DBNull.Value, c.DefaultValue);
            Assert.False(c.DesignMode);
            Assert.Equal("", c.Expression);
            Assert.Equal(0, c.ExtendedProperties.Count);
            Assert.Equal(-1, c.MaxLength);
            Assert.Equal("", c.Namespace);
            Assert.Equal(4, c.Ordinal);
            Assert.Equal("", c.Prefix);
            Assert.False(c.ReadOnly);
            Assert.Null(c.Site);
            Assert.Equal("test_table", c.Table.TableName);
            Assert.Equal("test3", c.ToString());
            Assert.False(c.Unique);
        }